Fluid tx Flashcards
How is water divided up within the body?
1/3 intra vascular
- within this 1/4 intravascular, 3/4 interstitial
2/3 intracellular
- need change in Na to affect water movement here
What is Starlings law?
Balance of oncotic and hydrostatic pressure within and outside capillaries
Potential complications from too much fluid?
- pulmonary oedema
- interstitial oedema (subcut oedema, organs, v function)
- 3rd spacing
> clinics, signs - pulm crackles
- peripheral oedema
- chemosis of the eyes
- bilateral serous nasal discharge
- jugular distension, pulsation
- increase body weight (weigh 3x a day)
- large left atrium on us
Which patients are at risk of fluid overload?
- cardiac or pulmonary disease
- oliguric/anuric renal failure
- geriatric cats
- hypoalbumenaemia
- Sepsis/SIRS
How does Tx of shock and dehydration differ?
Shock intravascular Dehydration interstitial (NOT INTRACELLUALR)
Goals for Tx of shock?
- fluid bolts to fill intravascular space
- Tx until 6 perfusion parameters Normal
- care to not give too much (at risk patients)
- defo no more than one blood volume (80ml/kg dog, 50ml/kg cat)
- Tx underlying causes
5 questions to think about wrt IVFT?
- Type
- Dose/rate (dose shock, rate dehydration)
- Additive
- Delivery
- When to stop
Outline board fluid types LOOK UP
> crystalloid - isotonic (Hartmanns, CSL, LRS, 0.9% nacl) - hypertonic (7.5% NACl) - hypotonic (0.45% NaCl, 5% Dextrose) > colloid (high oncotic pressure) - synthetic (Volulyte) - Natural (blood products, albumin)
Which fluids do you not use for shock treatment?
HypOOO tonic
Which fluids are balanced and which are not?
- Hartmanns
- LRS
- CSL
> Na, K, Cl, Ca, Lactate
Which fluids are not balanced?
- 0.9% NaCl
- Na and Cl only
What are the 3 main substances in balanced crystalloid a (Hartmanns etc) ? Why are they there?
> lactate
- metabolised to bicarbonate
- tx metabolic acidosis (which occour in shock)
potassium
- Some worry about ^ K but doesn’t usually cause hyperkalaemia as diuresis causes ^ renal excretion
calcium
- BEWARE chelates with sodium citrate preservative in blood products so don’t give together
Indications for isotonic crystalloids
- all causes hypovolaemic shock
- obstructive shock (GDV)
- vasodilatory shock
- dehydration maintInance
- diuresis (azotaemia, toxicity)
- Tx metabolic acidosis (Hartmanns, CSL, LRS)
- Tx metabolic alkalosis (0.9% Nacl)
Dose isotonic crystalloids?
- dogs 10-20ml/kg IV
- cats 5-10ml/kg IV
> over 15 minutes
> repeat up to 4 times (monitor, if no improvement after 2 doses, STOP)
Indications for hypertonic saline
- traumatic brain injury (can occour with hypoxia in cardiac arrest)
- cerebral oedema
- large breed dog (^ intravascular space quicker)
- CPR
- used commonly in equine
Contraindications for hypertonic saline?
- hyper/hyponatraemia
- dehydration
Doses of hypertonic saline
2-4ml/kg over 10 minutes
- once ONLY
- follow with isotonic crystalloids
How do colloids work?
Prevent fluid leaving intravascular space (DO NOT DRAW WATER IN FROM INTERSTITIAL SPACE !!)
Indications for artificial colloids
- severe hypoproteinaemia
- large dog
Potential adverse effects/contraindications for artificial colloids?
- kidney injury or renal failure
- coagulopathy
- ^ risk fluid overload
- sepsis (^risk kidney injury)
Dose of artificial colloids
- dogs 5-10ml/kg over 15 mins
- cats 2.5-5 ml/kg over 15 mins
- repeat up to 4 times
How does delivery of fluids differ between species ?
- small dog (fluid pump)
- medium large dog (pressure bag)
- cats (careful!!! 50ml syringe, by hand, or syringe driver, or pump with paediatric burette)
What is the maintainance fluid rate?
- normal daily fluid requirement
- isotonic crystalloids
> 2ml/kg/hr
What are the 3 components of fluid therapy (ongoing)?
Maintainance + replacement (dehydration) + ongoing losses
